1. Field of the Invention
The present invention relates to an image forming system configured to receive print jobs from an information processing unit and to perform image processing in an image forming apparatus which includes a plurality of paper feed units.
2. Description of the Related Art
Improvements to the performance of digital multifunction peripherals and printers have resulted in increased use of such image forming apparatuses in Print On Demand (POD). These types of image forming apparatuses applying POD include finisher functions, such as saddle stitch binding, case binding, and side stitching and staple binding, and often perform the series of operations from printing to binding.
POD applications sometimes use different types of paper for pages such as the cover, color pages or monochrome pages. The image forming apparatus includes a plurality of paper feed units and records the paper type of each paper feed unit. The combination of paper type and the respective pages in a print job is stored and the image forming apparatus searches the paper feed units for a paper type stated in the print job and feeds the paper from the paper feed unit for printing operations when the required paper type is available in the paper feed unit.
When the paper type required for the print job is not available in the paper feed unit, the operation unit of the image forming apparatus either displays a corresponding error message and terminates the printing operation, or performs the printing operation after determining an availability of a similar paper type to the designated paper type.
Japanese Patent Application Laid-Open No. 2005-266062 discusses a method related to the correlation of a paper type and paper feed unit in which an operation unit of the image forming apparatus designates the combination.
Japanese Patent Application Laid-Open No. 2005-144927 discusses a method of prompting a user to replace paper when the paper feed unit has not been opened and closed after a change in the paper setting to prevent image formation on the wrong type of paper.
These methods do not consider the required number of sheets for the print job which an information processing apparatus outputs to the image forming apparatus. Consequently, when, for example, the designated paper is set to a paper feed unit without a storage capacity for the required number of sheets for processing the print job, paper will run out during the printing process, thereby placing a burden on a user.
When operations from printing to binding are performed using a single image forming apparatus, the operation includes a mixture of pages such as the cover, color pages, monochrome pages or the Z-fold page. When the paper type is not adapted to the paper feed unit (cassette and deck), printing and copying will be performed using incorrect paper and result in lost costs.
More specifically, if the linkage of a cassette with the actual paper is not correctly executed in an image forming apparatus, when the required paper type for the print job is not available, another type of paper with the same size in the image forming apparatus is used. In this manner, when a print job is executed which should be performed using art paper of Company A in a certain cassette, the actual paper used for image formation may be copying paper from Company B.
Furthermore when the number of feedable sheets of the cassette in the image forming apparatus is not sufficient for the number of sheets required in the print job, an operator must supplement the paper on several occasions during the execution of the print job. For example, when printing a copy requested in the print job, although the specified number of sheets requires a total of 5000 sheets, if the paper is set to a cassette with a capacity of 500 sheets, the operator will have a troublesome operation of supplementing the paper at least on 10 occasions.